Powertrain, generic (extended)

P2AAE Diesel Fuel Presence Sensor Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2AAE is stored when the diesel presence sensor signal falls below the lowest value the input accepts, which points to a short to ground on the signal line or a sensor whose output has collapsed. Whether a low reading would otherwise stand for diesel or for gasoline is not published, so the code says nothing about the fuel in the tank, only that the reading cannot be used. No manufacturer documents P2AAE publicly. Ford's misfuelling patent US10611625B2 targets hybrids with sealed fuel tanks and watches the carbon canister temperature during refuelling, which shows that the task can be solved with sensors the vehicle already has. CARB requires out-of-range checks on inputs. Look first for chafed wiring near the tank, then at the sensor; P2AAF is the high counterpart.

Likely causes

Signal wire shorted to ground, often chafed on the underbody
Internal short in the sensor
Sensor supply or reference voltage missing

Symptoms

  • Check engine light on
  • Misfuelling protection inactive

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–400
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

diesel fuel presence sensorwiring harnessecm

Related codes

P2AAFP2AACP2AAD

References: law.cornell.edu, patents.google.com.